There currently exist many industrial uses of silicon tetrachloride (SiCl4). For example, SiCl4 is used in making high-surface area (fumed) silica, in the production of pure polycrystalline silicon used in the photovoltaic industry, and in the formation of very pure single-crystal silicon used in the semiconductor industry. Silicon tetrachloride is also used in the manufacturing process for optical fibers.
Conventionally, silicon tetrachloride has been made by several different reaction pathways, including (i) the reaction of silica with carbon and chlorine; (ii) the reaction of pyrolyzed rice hulls (which are rich in silica) with chlorine and carbon; (iii) the reaction of silicon carbide with chlorine; and (iv) the reaction between silica, silicon carbide and chlorine. Another route for forming silicon tetrachloride is to react tetraethylsilane with aluminum trichloride. In addition, technical grade SiCl4 is made industrially by treating metallurgical silicon with hydrochloric acid. Very pure SiCl4 is made industrially by the careful distillation of technical grade SiCl4.
In each of the reactions indicated above, a very large amount of energy is used in making silicon by the carbothermic reduction of silica. Thus conventional routes to forming silicon tetrachloride require an undesirably large amount of energy. In addition, some conventional routes to silicon tetrachloride suffer from low yields and the use of expensive materials in the construction of reactors that can withstand aggressive or severe reaction conditions, as well as the presence of other engineering challenges.